Where to have O2 sensor bung welded ?

[GiGs]

So, I have decided to purchase an AEM UEGO - I will have an exhaust shop drill the hole and weld the bung on for me.

The guy on the phone said to bring along a stainless steel nut (which I assume he means the bung) if not a mild steel one and just mark where I wanted the hole. I said that it may need to be an extended bung (due to the size of the pipe inside), he said use 2 nuts or he might be able to find a solution.....

**I have a full Yoshimura system installed**

Question is : Where is the best place to mount it ?

I saw a picture where someone on these forums mounted there O2 sensor where the cat would be on stock headers...from some research this seems like a bad position because it gets too hot ? I was thinking somewhere down the line but before the second piece of the exhaust (the muffler).

any help would be much appreciated,

cheers

[Alex]

Howdy! Curious about this myself. There is some info in this thread, had you seen this already?

[GiGs]

Yeap, that's the one - came across it and within about 5 minutes I had found another way to spend money on my bike It's worth it if you ask me...$280AU + / - a bit or $$$ for a new motor...

thanks for the reply

[GiGs]

I haven't measured the inside diameter of my exhaust (the header side) but I plan too, unless someone has specs and can post them but I found nothing

I believe the total length of the O2 sensor - a Bosch LSU4 - (included with the AEM UEGO) is 84mm. The threaded part is M18 with a 1.5mm thread pitch, from looking at some technical documents my understanding is that from the start of the thread to the end of the sensor is 30mm...

I'm trying to figure out how much space the sensor is going to take up in the exhaust...before purchasing everything (although I believe the AEM UEGO also comes with a bung..not sure if it's mild steel or stainless steel).

A standard bung is ? ? ? long

An extended bung (Innovate Motorsports) is 25mm long << This would need to be cut down.

cheers guys

[Alex]

I know this isn't going to help much, but if anyone searches for "ninjette bung" on google this is now the top hit, so we're obligated to come up with a good answer.

[GiGs]

ha ha ha I started seeing it pop up in my searches !

last post for now ....

in the thread that was mention by Alex, looking closely - a person with a stock pipe used a standard bung and a person with an Area P exhaust used an extended bung (would have thought that would be the other way around lol).

If I can use a standard bung good (I can pick a stainless steel one up for $15 about 5 minutes from me), if not I have to order an extended bung in from the US and i'll just have to wait.

Still no idea whether the AEM UEGO comes with a bung and if it does, what material it's made out of...dam eBay sellers !

Well, I have done my research throughly...i'm taking a break - hopefully someone can help

cheers

[GiGs]

just to update, a standard bung is 14mm (top to bottom)...and there is a bung included with the AEM UEGO, it's mild steel...

IF from the top of the thread to the bottom of the sensor is 30mm, and the bung (top to bottom) is 14mm ... 16mm of the sensor will be sticking into the pipe. Any more or less wouldn't be to bad either I think.

To me, this seems perfect...absolutely no reason for an extended bung or any reason to think that it will start to have a restrictive effect. In the meantime, it's time to buy buy buy


Still the question remains un-answered....where is the best place to make the hole for the O2 sensor.

cheers guys

[FrugalNinja250]

Though WBO2 sensors are typically heated, you do want to mount the sensor as close to the beginning of the exhaust as possible, but still be in the combined stream from both cylinders. That means somewhere just after the two separate pipes join to one. Other than that, just mount it so that it isn't sticking out such that road debris can hit it and so that the wiring doesn't come in contact with moving/hot parts.

[GiGs]

Cheers, that's what I was thinking...well I shall post back when it's all done (maybe a few days or a week)

cheers guys

[Racer x]

I put my sensor at the Y where the two pipes come together You have to get the angle right .It will hit the fairing or the engine if you get it wrong. Mine is for a data logger.

[GiGs]

hmmm ok I see - three questions

You have used an extended bung...is this really necessary ?

Would you be able to tell me how much of the sensor sticks into the pipe (e.g 10mm of it sticks in the pipe) from memory ?

What sensor are you using ?

cheers mate

[HKr1]

Sensor needs to stick into the exhaust stream for sure

[dubojr1]

Originally Posted by HKr1

Sensor needs to stick into the exhaust stream for sure

Actually Kerry at Area P says minimal protrusion is best but debatable....

Originally Posted by kbryant

Sorry for the slightly long post, but I'll condense it as much as possible.

To answer some of those questions: The benefits of having an A/F gauge, narrowband, wideband, closed loop system, etc. on a carburated street bike is really more of a cool tech gadget than anything. When dyno tuning, of course we use these tools (both carburated and FI) to determine the best baseline settings. This data is documented and distributed for you to use. Essentially then for the customer to tune, the basic jetting specs are a known entity. But for sake of argument, let's say you have an A/F reading on your gauge/meter riding through a particular climate/elevation that you feel is outside your desired perameters. Are you going to pull over and change the jetting in your carburators to compensate for that? Highly doubtfull. In most cases, we would simply stick with our baseline setting that we tuned to in the first place and deal with the differences in performance. Your particular geograpical location will continue to change. Henceforth, in a perfect world, you would want to continuosly change your jetting. But is it worth the differences in performance to do this? Only you can decide this. Same with the differences in summer and winter blend fuels; performance will change and if you have a carburated vehicle, will you make adjustments? With carbs, it's simply impractable to continually address it so we "settle" for a decent baseline running condition. So again, very cool gadget, but what will you do with this new tool on your carburated streetbike? Once your bike is jetted properly, it would be extremely rare that you would see really big swings in the A/F readings (obviously there are exceptions). As indicated, lot's of climate variables but lets take one example: You normally ride at sea level to say 1500'. Your bike is jetted correctly and you love the way it runs. Now your going for a ride up to the mountains (say 4000' elevation). Your A/F meter is going to show a rich condition. For every 1000' of elevation you lose approximately 2 - 3% of your power. The air is more dense so you are getting a smaller amount of it. In "most" cases, you simply deal with it. Sure you'll notice it more on a smaller bike, but your not going to pull over and make changes (are you?).

Now, with a FI equipped bike, you have much more higher tech options. The standard "closed loop" OEM systems are known as "narrowband". They only sample a small range and essentially switch from lean to rich based primarely on stoichiometric (14.7:1) and little else in-between. Contrary to popular belief, the stoichiometric magic number is not what we tune for. "Most" times we tune in the 12.8 - 13.5 range for best overall power and throttle response. With "wideband" tuning sensors, we now have the ability to tune an engine to a desired ratio table. For example on a Dynojet PCV with autotune, it samples a far broader range whether it be based on rpm or throttle position. Simple put, prior to the autotune option being enabled (wideband/oxygen sensor), we design a map for specific set of numbers we want and load it into the PCV. Then when the autotune is enabled, it will continuously "tune" to those settings under most all conditions. No arguement, it's a very sweet system.

But... will you truly be able to appreciate the difference in autotune mode, over a loaded set map? It really depends on how and where you ride. If you ride in a particular area and conditions, you won't be able to appreciate the benefits. If you ride/live at sea level, warmer temps and higher humidity, but then go up to 6000', colder, less humid conditions, wideband and autotune will benefit you.

On bikes that come with oxygen sensors stock (oem), we disable them (plug them) and simply design a correct map (PC3/V) and load it. Primarily the reason is that the "narrowband" logic of the oem unit will try and override the created map. So it somewhat defeats the idea of a purpose designed map. The beauty of this map, is that it can be manually manipulated based on whatever you would like to change (whether based on throttle position or rpm). But again, there is no debate on the benefits of a real time, wideband autotune setup. Doesn't get any better than that. Tuning streetbikes is all about compromise in most cases. True wideband/autotune removes the compromise in most cases.

To address the oxygen sensor bung questions: We install an oxygen sensor bung in the stock location on all Area P systems shipped to Europe for FI equipped bikes. Although we do recommend disabling the oem narrowband unit, putting a plug in the bung, and installing a PCV for best performance. For anyone with a non-FI bike who would like a 02 Bung installed, you can simply request it at the time you place your order. Or you can send us your system and we can install one for you. We have both 12mm & 18mm bungs. Kawasaki and/or wideband/bosch sensors take the 18mm bung.

For the question on oxygen sensor protrusion into the exhaust stream. Definetly beneficial to have only a minimum of protrusion from the sensor. How much it actually affects performance is debatable, depending on the engines state-of-tune and diameter of the tube it is installed in.

For the question about the slip-fit adaptor tube with bung installed. We have probably been doing those for over 20 years. They work ok. The down side is the available space for practically routing the wiring to/from the sensor. Also, we find that taking the readings closer to the collector area creates a more accurate "tune" for wideband systems. If you are doing it simply to get a general base reading on your A/F without finely accurate real time tuning, then this slip-fit adaptor with bung will suffice.

[HKr1]

Originally Posted by dubojr1

Actually Kerry at Area P says minimal protrusion is best but debatable....

yeah, top of the sensor in the exhuast flow. Look at any stock car/truck/bike

[Racer x]

I use the sensor( Bosch) that came with the Innovat lm2 datalogger.the tip bairly sticks into the pipe. It is not like most O2 sensors that breath from the side. This sensor only has holes at the tip.it is no restriction at all.

I do all my tuning on the dyno. There is no better way to set up the bike for racing. But Landspeed racing is real world. I must have the data from th e last run in order to make an intelegent change or no change for the next run

[GiGs]

hmm I am assuming that the Bosch sensor you use (Racer X) is equivalent if not the same as the one provided with the AEM UEGO (Bosch LSU 4.2)

If you (Racer X) say it barely sticks into the pipe, and your using an extended bung (which I will assume to be 25mm top to bottom ?) ...... then why don't I get an extended bung, take a few mm's off and have the best of both worlds ?

I'm still waiting on the AEM UEGO to arrive, once it does I can make measurements and compare a standard bung to an extended bung.

HKr1 thanks for the picture, now I see where it should be mounted



sorry if it seems like i'm posting to much, just trying to get as much information as possible before I get someone to drill a hole and weld something to my pricey exhaust

[GiGs]

My O2 wideband bung is in Oz so I should receive it tomorrow (maybe have it welded in that day or the next) - less than 14.7 is rich and more than 14.7 is lean. Maximum power is between 12.5 to 13.3


If you have a wideband sensor or you have dyno'ed your bike please comment on what your A/F ratio is along with jet size, needle position etc

cheers

[greg737]

Here's why I used an "extended length" bung on my project......

During my build I discovered that I needed to use an "extended length" bung because of the narrow (when compared to an average car's exhaust) diameter of the Area P EX-250 exhaust. If I'd used a standard depth bung the oxygen sensor would have protruded way too far into the relatively narrow exhaust pipe.

I didn't do the math to figure out what percent of the Area P exhaust tube would be blocked by the oxygen sensor if I'd used a standard depth bung, but when I was preparing to weld it I mocked up with the standard length bung and the sensor really filled the tube and just looked wrong.

With the standard length bung it looked like the oxygen sensor would have had a restricting effect on the exhaust gas flow (possibly even to the point of negating the advantage of installing the Area P in the first place).

With the extended length bung only the nose of the sensor peeks out into the flow of gases in the Area P exhaust tube. As far as I can tell, this setup works perfectly. It updates/varies quickly with throttle changes just like it's supposed to do.

[GiGs]

That's why I chose an extended length bung, if it happens to be to long (it's 25mm SS from Innovate Motorsports) then I can sand it down or cut some off but I think it will be ok

I had to wait longer, but i'd rather do it properly then screw an expensive exhaust system...as for where I will mount it, i'm thinking about mounting it where the cat on a standard system will be (where the 2 pipes come onto a Y like Racer X said).

cheers

[GiGs]

Ok, so I got the extended bung today...screwed the sensor in only hand tight and the tip of the sensor (that looks like \__/ ) pokes out past the end of the bung by about 5mm. Once tightened down it will probably poke out a few more mm but it's perfect.

So, to anyone wondering, an extended length bung (25mm) is what you need.

I have an appointment with the exhaust shop tomorrow, i'm mounting it right before the 'end weld' at the end of the Y. When I did a test mock-up the sensor sits in a little pocket at the front of the crankcase, it doesn't hit anything although I didn't have the fairing on (i'll have a look now). I'm confident it will be ok since it's 'behind' the oil cover if that all makes sense

I'll wire it up tonight...and post some pics of things tomorrow

appreciate all the help guys !

cheers

[GiGs]

Sorry for no update, got busy, crappy weather etc...

Here are some pictures of where I had the O2 sensor bung welded:





As you can see it's just perfect

That's a 25mm Stainless Steel bung from Innovate Motorsports, the wires inside the tube are protected and will not melt.

The gauge is good quality, only downfall is with a clear windscreen in the day time you cannot see the leds (I have a dark smoke puig waiting to be put on). I wired it up with a 12v 30A relay (overkill) with a fuse inbuilt in the relay.

Once I get everything tuned properly i'll take a few more pictures. I plan to customize the gauge by replacing the 3 red 8 digit number displays with blue ones. Maybe even customize my gauge cluster with white/red leds too while i'm at it

cheers guys

[greg737]

Here's a picture of my 2005's front fairing (removed from the bike).

I mounted my Innovate O2 sensor guage on a little metal bracket that I attached to the turn signal mounting bolt. On the other side you can see my clock (mounted to the other turn signal bolt).

This puts them in a very visible position when viewed during normal riding and direct sunlight almost never falls on the guage. My O2 guage is the red-digital model. This mounting postion is also very weather-proof. The clock and the O2 guage stay clean and dry.

Since both the O2 guage and the clock aren't "primary" instruments I didn't want to try and mount them up with the tach and speedo.

[rwheelz]

I found this thread while searching about oxygen sensors. I bought the Tyga exhaust which has a bung for the stock ninja 250 FI oxygen sensor. However, my AEM wideband sensor does not fit into the bung. The threading is the same size, but the end of the sensor itself is too big to fit down into the hole. Does anyone know what the size of the stock FI 250 oxygen sensor is? Or whether there are any wideband sensors available that are smaller in diameter at the sensing portion?